By Taylor Sienkiewicz, Summit Daily FRISCO — On the morning of Wednesday, Nov. 13, Keystone Resort and Breckenridge Ski Area announced the opening of additional base areas and terrain for Saturday. Keystone will open the Mountain House base area and the Peru Chair. Keystone spokeswoman Loryn Roberson said more Saturday terrain might be announced Friday. Breckenridge will open its Peak 9 base area and the intermediate Bonanza and Crosscut runs, the beginner Cashier, Lower American, Silverthorne and Lower Sawmill runs and the Upper Park Lane terrain park. On Wednesday afternoon, Arapahoe Basin Ski Area announced its Sundance beginner run would open Thursday.